Sergey Danishevskiy

Sergey Danishevskiy is the CEO of Selleris, a GTM engineering agency that builds and continuously improves client-owned revenue systems on HubSpot for B2B SaaS and tech-enabled SMBs with mid-market ambitions, and the founder of Selleris Connect, the client collaboration portal Selleris uses for its own delivery.

Selleris, which he leads, has delivered 400+ CRM projects directly and through implementation partners since 2017, with a 5+ years average client relationship. The company is headquartered in New York, with an engineering office in Warsaw.

Sergey designed Selleris Revenue Loop, a Build & Improve program that treats the revenue system as one connected architecture across demand generation, prospecting, sales, onboarding, retention and expansion. His approach starts with the constraint holding growth back rather than with another tool: the Free Revenue Diagnostic establishes the growth ambition, the current constraint and the cost of delay, and only then proposes what to build first. AI agents prepare work before they are allowed to act; customer context is carried across handoffs with SPICED by Winning by Design; and the client keeps control of the accounts, data and delivered assets. Commercially, Selleris works on fixed prices agreed before work starts and is paid per verified result, with no upfront Selleris delivery fee and no automatic retainer.

Sergey works directly with founders and executive teams on the decision to invest in their revenue system, and stands behind the result Selleris agrees to deliver.